Current mainstream smartphones are equipped with a flash to improve the dark-shooting effect. Although the LED light source is a cold light source, it has a luminous efficiency of approximately 1001m/W, and an electro-optic conversion efficiency of about 20%-30%. In other words, about 70% of the electrical energy becomes heat. As mobile phones are getting more and more compact, the CPU, the screen, the battery and the like have become the main sources of heat, while the design of mobile phones has never considered enhancing the heat dissipation of the LED flash which serves as an auxiliary light source for photographing. Consequently, excessive use will result in poor heat dissipation, high heating temperature, and thus reduction of the life of the LED flash.